Video coding method and apparatus utilizing combination of diverse block partitioning structures

ABSTRACT

The present invention relates to a block partitioning structure from among the video coding schemes and to a method and apparatus for encoding and decoding the block partitioning structure, the method comprising the steps of: acquiring block partitioning data; partitioning a block by means of the acquired block partitioning data; and encoding and decoding by means of the partitioned block. The encoding and decoding method and apparatus according to the present invention has the benefit of improving encoding efficiency with respect to the existing video compression schemes.

RELATED APPLICATIONS

This application is a continuation application of the InternationalPatent Application Serial No. PCT/KR2016/011332, filed Oct. 11, 2016,which claims priority to the Korean Patent Application Serial No.10-2016-0130474, filed Oct. 10, 2016. Both of these applications areincorporated by reference herein in their entireties.

TECHNICAL FIELD

The present invention relates to an image processing scheme and, moreparticularly, to a block partitioning structure in video compressionschemes, and a method and an apparatus for performing the partitioningon the block partitioning structure.

BACKGROUND

As the demand for high-resolution, high-definition video increases, theneed for high-efficiency video compression technology fornext-generation video services has emerged. Based on this need, thestandardized MPEG and VCEG jointly established the Joint CollaborativeTeam on Video Coding (JCT-VC) of the video compression standardizationof H.264/AVC, and completed the standardization for HEVC, which is thelatest international video compression standard established January2013.

In the video compression technique, a block partitioning structurerefers to a unit in which encoding and decoding are performed, and aunit to which main encoding and decoding techniques such as predictionand transform are applied. As the video compression technology develops,the magnitude of blocks for performing encoding and decoding isgradually increasing, and in terms of partitioning type of blocks, morevarious partitioning forms are supported. In addition, the videocompression is performed using units subdivided according to roles ofblocks as well as units for performing encoding and decoding. In theHEVC standard, video coding and decoding are performed using unit blockssubdivided according to a block partitioning structure of quad-tree typeand roles of prediction and transform. In addition, various forms ofblock partitioning structures such as a Quad-Tree plus Binary-Tree(QTBT) which is a form of a combination of a quad-tree and abinary-tree, a block partitioning structure of any form, and the likehave been proposed for improving video encoding efficiency.

SUMMARY

It is an object of the present invention to provide a method andapparatus capable of improving encoding efficiency compared to theexisting video compression schemes by utilizing a combination of diverseblock partitioning structures.

It is to be understood, however, that the technical scope of the presentinvention is not limited to the above-described technical problems, andother technical problems may exist.

In order to solve the above problems, a video coding method andapparatus according to an embodiment of the present invention includes ablock partitioning information acquisition unit, a block partitioningperformance unit, and a block encoding/decoding unit.

In order to solve the above problems, a video coding method andapparatus according to an embodiment of the present invention includes ablock partitioning information parsing unit, a determination unitrelating to whether an additional block partitioning information isrequired, and an additional block partitioning information acquisitionunit.

In order to solve the above problems, a video coding method andapparatus according to an embodiment of the present invention includes acolor format determination unit of a current picture, a luminance andchrominance component block magnitude comparing unit, an additionalblock partitioning information acquisition unit, and a blockpartitioning performance unit.

An object of the present invention is to provide a video coding methodand apparatus that efficiently performs block partitioning and improvescoding efficiency through the block partitioning in a video codingmethod and apparatus utilizing a combination of diverse blockstructures.

According to an embodiment of the present invention, encodingperformance can be improved by utilizing a combination of diverse blockpartitioning forms.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration of a video encodingapparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a videodecoding apparatus according to an embodiment of the present invention.

FIG. 3 is a conceptual diagram illustrating types of various blockpartitioning and blocks with various block partitioning according to anembodiment of the present invention.

FIG. 4 is a table showing a syntax for supporting a block structure withvarious block partitioning according to an embodiment of the presentinvention.

FIG. 5 shows an example of a color element according to a color formatfor one block according to an embodiment of the present invention.

FIG. 6 shows an example in which a block partitioning structure is usedin the same manner for each color element according to an embodiment ofthe present invention.

FIG. 7 shows an example in which a block partitioning structure is useddifferently for each color element according to an embodiment of thepresent invention.

FIG. 8 is a flowchart illustrating the performing of partitioning anddecoding on blocks in a video decoder according to an embodiment of thepresent invention.

FIG. 9 is a flowchart of a block partitioning performance unit accordingto an embodiment of the present invention.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention will be described indetail with reference to the drawings attached thereto, so that thoseskilled in the art can easily carry out the present invention. Thepresent invention may, however, be embodied in many different forms andshould not be construed as limited to the embodiments set forth herein.In order to clearly illustrate the present invention, parts not relatedto the description are omitted, and similar parts are denoted by likereference characters throughout the specification.

Throughout this specification, when a part is referred to as being‘connected’ to another part, it includes not only a case where they aredirectly connected but also a case where the part is electricallyconnected with another part in between.

In addition, when a part is referred to as ‘comprising’ an elementthroughout the specification, it is understood that the element mayinclude other elements as well, without departing from the otherelements unless specifically stated otherwise.

The term ‘a step of doing something’ or ‘a step of something’ usedthroughout this specification does not mean a step for something.

Also, the terms first, second, etc. may be used to describe variouscomponents, but the components should not be limited by the terms. Theterms are used only for the purpose of distinguishing one component fromanother.

In addition, the components shown in the embodiments of the presentinvention are shown independently to represent different characteristicfunctions, but that does not mean that each component consists ofseparate hardware or one software constituent unit. That is, eachcomponent is described by arranging each component for convenience ofexplanation, and at least two components of components may be combinedto form one component or one component may be partitioned into aplurality of components to perform functions. The integrated embodimentsand the separate embodiments of each of these components are alsoincluded in the scope of the present invention without departing fromthe essence of the present invention.

In the various embodiments of the present invention described below, thecolor format refers to types of color components constituting onepicture, and the encoding block or encoding unit may be collectivelyreferred to as including a single block or a unit in which encoding anddecoding are performed in video coding. The color format is not limitedto a YUV format, and may be collectively referred to as including allkinds of a plurality of color formats according to color components forconstituting one picture.

Hereinafter, a video coding method and apparatus utilizing a combinationof diverse block partitioning structures proposed according to anembodiment of the present invention will be described in detail withreference to FIG. 9.

FIG. 9 is a flowchart of a block partitioning performance unit accordingto an embodiment of the present invention.

The block partitioning information acquiring unit 830 according to oneembodiment includes a block partitioning information parsing unit 920,an additional block partitioning information determination unit 930, anadditional block partitioning information acquisition unit 940, and ablock partitioning information storage unit 950.

The block partitioning information parsing unit 930 performs parsing onblock partitioning information from the bitstream to acquire the blockpartitioning information.

The additional block partitioning information determination unit 930determines whether additional partitioning information is required inpartitioning the current block by using a color format of currentpicture, block depth information, block position information within apicture, block size information, and the like.

When the additional block partitioning information determination unit930 determines that the additional block partitioning information isneeded, the additional block partitioning information acquisition unit940 acquires additional block partitioning information required fordetermining the block partitioning structure of the current block. Theadditional block partitioning information required for determining thepartitioning structure of the current block may be obtained by parsingfrom the bitstream or obtained using the color format of currentpicture, the block depth information, the block position informationwithin the picture, the size information of the block, and the likewithout parsing from the bitstream.

The block partitioning information storage unit 950 stores the blockpartitioning information acquired by the block partitioning informationparsing unit 920 and the additional block partitioning informationacquisition unit 940.

Hereinafter, embodiments of the present invention will be described indetail with reference to the drawings attached thereto, so that thoseskilled in the art can easily carry out the present invention. Thepresent invention may, however, be embodied in many different forms andshould not be construed as limited to the embodiments set forth herein.In order to clearly illustrate the present invention, parts not relatedto the description are omitted, and similar parts are denoted by likereference characters throughout the specification.

Throughout this specification, when a part is referred to as being‘connected’ to another part, it includes not only a case where they aredirectly connected but also a case where the part is electricallyconnected with another part in between.

In addition, when a part is referred to as ‘comprising’ an elementthroughout the specification, it is understood that the element mayinclude other elements as well, without departing from the otherelements unless specifically stated otherwise.

The term ‘a step of doing something’ or ‘a step of something’ usedthroughout this specification does not mean a step for something.

Also, the terms first, second, etc. may be used to describe variouscomponents, but the components should not be limited by the terms. Theterms are used only for the purpose of distinguishing one component fromanother.

In addition, the components shown in the embodiments of the presentinvention are shown independently to represent different characteristicfunctions, and that does not mean that each component consists ofseparate hardware or one software constituent unit. That is, eachcomponent is described by arranging each component for convenience ofexplanation, and at least two components of components may be combinedto form one component or one component may be partitioned into aplurality of components to perform functions. The integrated embodimentsand the separate embodiments of each of these components are alsoincluded in the scope of the present invention without departing fromthe essence of the present invention.

In the various embodiments of the present invention described below, thecolor format refers to types of color components constituting onepicture, and the encoding block or encoding unit may be collectivelyreferred to as including a single block or a unit in which encoding anddecoding are performed in video coding. The color format is not limitedto a YUV format, and may be collectively referred to as including allkinds of a plurality of color formats according to color components forconstituting one picture.

Hereinafter, a video coding method and apparatus utilizing a combinationof diverse block partitioning structures proposed according to anembodiment of the present invention will be described in detail withreference to FIG. 9.

FIG. 1 is a block diagram illustrating a video encoding method andapparatus according to an embodiment of the present invention.

The video encoding method and apparatus according to an embodimentincludes an inter prediction unit 120, an intra prediction unit 125, asubtraction unit 130, a transform unit 140, a quantization unit 150, anentropy encoding unit 160, an inverse transform unit 145, an inversequantization unit 155, an adding unit 135, an in-loop filter unit 180,and a reconstruction picture buffer 190.

The inter prediction unit 120 performs motion prediction by using theinput image 110 and the reconstructed image stored in and thereconstruction picture buffer 190, thereby generating a predictionsignal.

The intra prediction unit 125 performs spatial prediction by using pixelvalues of pre-reconstructed neighboring blocks that are adjacent to thecurrent block to be encoded, thereby generating a prediction signal.

The subtraction unit 130 uses the input image and the prediction signalgenerated through the inter prediction unit 120 or the intra predictionunit 125, thereby generating a residual signal.

The transform unit 140 and the quantization unit 150 perform transformand quantization on the residual signal generated through thesubtraction unit 130, thereby generating a quantized coefficient.

The entropy encoding unit 160 performs entropy encoding on the encodinginformation such as syntax elements and quantized coefficients definedin the video encoder, thereby outputting the bitstream.

The inverse transform unit 145 and the inverse quantization unit 155receive the quantized coefficients and perform inverse quantization andinverse transform in order, thereby generating a reconstructed residualsignal.

The adding unit 135 generates a reconstructed signal using theprediction signal generated through the inter prediction unit 120 or theintra prediction unit 125 and the reconstructed residual signal.

The reconstructed signal is transmitted to the in-loop filter unit 180.The reconstructed picture to which the filtering is applied is stored inthe reconstruction picture buffer 190, and may be used as a referencepicture in the inter prediction unit 120.

FIG. 2 is a block diagram showing the configuration of a video decodingapparatus and method according to an embodiment of the presentinvention.

The video decoding apparatus and method according to one embodimentincludes an entropy decoding unit 210, an inverse quantization unit 220,an inverse transform unit 230, an intra prediction unit 240, an interprediction unit 250, adding unit 260, an in-loop filter unit 270, and areconstruction picture buffer 280.

The entropy decoding unit 210 decodes the input bitstream 200 andoutputs decoding information such as syntax elements and quantizedcoefficients.

The inverse quantization unit 220 and the inverse transform unit 230receive a quantizated coefficient and perform inverse quantization andinverse transform in order, thereby outputting a residual signal.

The intra prediction unit 240 performs spatial prediction by using pixelvalues of the pre-reconstructed neighboring blocks adjacent to thecurrent block to be decoded, thereby generating a prediction signal.

The inter prediction unit 250 performs motion compensation using amotion vector extracted from the bitstream and a reconstructed picturestored in the reconstruction picture buffer 280, thereby generating aprediction signal.

The prediction signals output from the intra prediction unit 240 and theinter prediction unit 250 are summed with the residual signal throughthe adding unit 260 and the reconstructed signal generated on aper-block basis includes the reconstructed image.

The reconstructed image is transferred to the in-loop filter unit 270.The reconstructed picture to which the filtering is applied is stored inthe reconstruction picture buffer 280 and may be used as a referencepicture in the inter prediction unit 250.

FIG. 3 is a conceptual diagram illustrating types of various blockpartitioning and blocks with various block partitioning according to anembodiment of the present invention.

A video coding method and apparatus utilizing diverse block partitioningaccording to an embodiment includes block partitioning forms including anon-partitioned block 310, a horizontally partitioned block 320, avertically partitioned block 330, four-partitioned block 340, and ablock structure 350 having diverse block partitioning.

According to an embodiment, the non-partitioned block 310 includes aform in which one encoding block is not partitioned, and thehorizontally partitioned block 320 according to an embodiment includes aform in which one encoding block is horizontally partitioned. Inaddition, the vertically partitioned block 330 according to anembodiment includes a form in which one encoding block is verticallypartitioned, and the four-partitioned block 340 includes a form in whichone encoding block is vertically and horizontally partitioned. The oneencoding block includes both a square block and a non-square block.

The block structure 350 having diverse block partitioning according toan embodiment includes a block structure of a form in which blocks 310,320, 330, and 340 of diverse block partitioning forms are combined. Inthe block partitioning structure according to the embodiment, the mostupper block 350 may be partitioned into four sub-blocks, i.e., a firstsub-block 351, a second sub-block 352, a third sub-block 353, and afourth sub-block 354. The first sub-block 351 according to an embodimentis a block represented by the block partitioning form of the block 310of a non-partitioned form, and the second sub-block 352 is a blockrepresented by block partitioning of the block 340 of a four-partitionedform. The one encoding block may be partitioned into one or moresub-blocks, and the partitioned sub-blocks may be repeatedlypartitioned. The second sub-block 352 is partitioned into foursub-sub-blocks, and each sub-sub-block indicates a block represented byblock partitioning of the non-partitioned block 310. The third sub-block353 is a block represented by the block partitioning of the horizontallypartitioned block 320 and the lower end rectangular block 356 of thesub-sub-blocks is a block represented by block partitioning of thevertically partitioned block 330. The fourth sub-block 354 is a blockrepresented by block partitioning of the four-partitioned block 340, andthe first sub-sub-block and the third sub-sub-block of the fourthsub-block are blocks represented by block partitioning of the verticallypartitioned block 330. Herein, the third sub-sub-block represents anembodiment in which additional vertical partitioning is performed.

FIG. 4 is a table showing a syntax for supporting a block structure withvarious block partitioning according to an embodiment of the presentinvention.

The video coding method and apparatus according to an embodiment of thepresent invention includes partitioning information 410 regardingwhether or not to partition a block into four sub-blocks, partitioninginformation 420 regarding whether or not to partition a block into twowhen the block is not partitioned into four sub-blocks, and directioninformation 430 regarding two-partitioning direction, in order to use ablock structure of diverse block partition forms. The partitioninginformation 420 regarding whether or not to partition a block into twosub-blocks and the direction information 430 regarding two-partitioningdirection include information necessary for partitioning one encodingblock into two sub-blocks, and may be transmitted in a form of two flagsor in a form of information combined into one.

FIG. 5 illustrates an example of a color element according to a colorformat for one block according to an embodiment of the presentinvention.

As an example of color element according to color format according to anembodiment of the present invention, among color formats, thisspecification shows a YUV 420 format 510 in which a size of a luminancecomponent is different from a size of a chrominance component, and a YUV444 format 520 in which a size of a luminance component is the same as asize of a chrominance component. In case of the color format in whichthe luminance component and the chrominance component are different fromeach other in size, a size of the luminance component block 511 and thechrominance component blocks 512 and 513 is different from each other inconstructing one encoding block. In case of the color format in whichthe luminance component and the chrominance component is the same in thesize, the size of the luminance component block 521 and the chrominancecomponent blocks 522 and 523 is the same in constructing one encodingblock. However, in the present specification, the color format in whichthe size of the luminance component and the chrominance component isdifferent from or the same as each other is not limited to the colorformat constituted with the luminance component and the chrominancecomponent, and includes classification according to component rate ofeach color element, such as various color formats such as RGB, XYZ, andthe like.

FIG. 6 shows an example in which a block partitioning structure is usedin the same manner for each color element according to an embodiment ofthe present invention.

A video encoding method and apparatus according to an embodiment usesthe same block partitioning structure in the luminance component blockand the chrominance component block regardless of a color format. Thevideo encoding method and apparatus according to an exemplary embodimentmay determine block partitioning structures by using the same blockpartitioning information in the luminance component block 611 and thechrominance component blocks 612 and 613 of a color format 610 in whichthe size of the luminance component and the chrominance component isdifferent from each other. The video encoding method and apparatusaccording to an exemplary embodiment may determine block partitioningstructures by using the same block partitioning information in theluminance component block 621 and the chrominance component blocks 622and 623 of a color format 620 in which the size of the luminancecomponent and the chrominance component is the same.

FIG. 7 shows an example in which a block partitioning structure is useddifferently for each color element according to an embodiment of thepresent invention.

The video coding method and apparatus according to an embodimentselectively uses the same or different block partitioning structure inthe luminance component block and the chrominance component blockaccording to the color format. The video encoding method and apparatusaccording to an embodiment may determine block partitioning structuresby using different block partitioning information in the luminancecomponent block 711 and the chrominance component blocks 712 and 713 ofa color format 710 in which the size of the luminance component and thechrominance component is different from each other. Herein, theluminance component block 711 and the chrominance component blocks 712and 713 may be partitioned using different block partitioningstructures, based on the block size and the encoding block partitioningdepth information. In addition, the video encoding method and apparatusaccording to an embodiment may determine block partitioning structuresby using the same block partitioning information in the luminancecomponent block 721 and the chrominance component blocks 722 and 723 ofa color format 720 in which the size of the luminance component and thechrominance component is the same.

The video coding method and apparatus according to an embodiment mayselectively use the block partitioning structure of the luminancecomponent blocks 711 and 712 and the chrominance component blocks 712,713, 722, and 723, in accordance with the color format 710 in which thesize of the luminance component and the chrominance component isdifferent from each other and the color format 720 in which the size ofthe luminance component and the chrominance component is the same.

FIG. 8 is a flowchart illustrating the performing of partitioning anddecoding on blocks in a video decoder according to an embodiment of thepresent invention.

The video coding method and apparatus according to an embodiment mayinclude a block partitioning information acquisition unit 820, a blockpartitioning performance unit 830, and a block decoding unit 840.

The block partitioning information acquisition unit 820 acquires andoutputs encoding information on block partitioning from the bitstream.

The block partitioning performance unit 830 performs block partitioningusing the encoding information on the block partitioning extracted bythe block partitioning information acquisition unit 820.

The block decoding unit 840 performs decoding on each decoding unitpartitioned through the block partitioning performance.

The present invention can be used for manufacturing such as broadcastingequipment manufacturing, terminal manufacturing, and the like, andindustries related to source technology.

What is claimed is:
 1. A video decoding method, comprising: acquiring,from a bitstream, block partitioning information of a current blockhaving a tree-based partitioning structure; performing blockpartitioning on the current block by using the acquired blockpartitioning information; and decoding sub-blocks resulting from theblock partitioning on the current block, wherein the block partitioninginformation includes first partitioning information indicating whetheror not to partition a block into four sub-blocks, second partitioninginformation indicating whether or not to partition a block into twosub-blocks and partitioning direction information indicating whether adirection of the block partitioning is a horizontal direction or avertical direction, and wherein the second partitioning information andthe partitioning direction information is respectively acquiring fromthe bitstream, wherein acquiring the block partitioning informationcomprises: parsing the first partitioning information from thebitstream; determining whether additional block partitioning informationis required, according to at least one of the parsed first partitioninginformation, partitioning depth information of the current block, or asize of the current block; and parsing the additional block partitioninginformation from the bitstream, in response to the determination thatthe additional block partitioning information is required, wherein theadditional block partitioning information includes the secondpartitioning information and the partitioning direction information,wherein the current block is divided into a luminance component blockand a chrominance component block; and wherein the block partitioninginformation is parsed for the luminance component block and thechrominance component block, respectively, wherein performing the blockpartitioning on the current block comprises: determining a blockpartitioning structure of the luminance component block based on theblock partitioning information of the luminance component block; anddetermining a block partitioning structure of the chrominance componentblock based on the block partitioning information of the chrominancecomponent block, and wherein the block partitioning structure of thechrominance component block is determined independent of the luminancecomponent block.
 2. A video encoding apparatus, performing: determiningblock partitioning information of a current block having a tree-basedpartitioning structure; performing block partitioning on the currentblock by using the block partitioning information; and encodingsub-blocks resulting from the block partitioning on the current block,wherein the block partitioning information includes first partitioninginformation indicating whether or not to partition a block into foursub-blocks, second partitioning information indicating whether or not topartition a block into two sub-blocks and partitioning directioninformation indicating whether a direction of the block partitioning isa horizontal direction or a vertical direction, and wherein the secondpartitioning information and the partitioning direction information isdetermined and encoded at the video encoding apparatus, respectively,wherein determining the block partitioning information comprises:determining the first partitioning information; determining whetheradditional block partitioning information is required, according to atleast one of the determined first partitioning information, partitioningdepth information of the current block, or a size of the current block,and determining the additional block partitioning information, inresponse to the determination that the additional block partitioninginformation is required, wherein the additional block partitioninginformation includes the second partitioning information and thepartitioning direction information, wherein the current block is dividedinto a luminance component block and a chrominance component block,wherein the block partitioning information is determined and encoded forthe luminance component block and the chrominance component block,respectively, wherein performing the block partitioning on the currentblock comprises: determining a block partitioning structure of theluminance component block based on the block partitioning information ofthe luminance component block; and determining a block partitioningstructure of the chrominance component block based on the blockpartitioning information of the chrominance component block, and whereinthe block partitioning structure of the chrominance component block isdetermined independent of the luminance component block.